{"id":"CVE-2024-50301","summary":"security/keys: fix slab-out-of-bounds in key_task_permission","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nsecurity/keys: fix slab-out-of-bounds in key_task_permission\n\nKASAN reports an out of bounds read:\nBUG: KASAN: slab-out-of-bounds in __kuid_val include/linux/uidgid.h:36\nBUG: KASAN: slab-out-of-bounds in uid_eq include/linux/uidgid.h:63 [inline]\nBUG: KASAN: slab-out-of-bounds in key_task_permission+0x394/0x410\nsecurity/keys/permission.c:54\nRead of size 4 at addr ffff88813c3ab618 by task stress-ng/4362\n\nCPU: 2 PID: 4362 Comm: stress-ng Not tainted 5.10.0-14930-gafbffd6c3ede #15\nCall Trace:\n __dump_stack lib/dump_stack.c:82 [inline]\n dump_stack+0x107/0x167 lib/dump_stack.c:123\n print_address_description.constprop.0+0x19/0x170 mm/kasan/report.c:400\n __kasan_report.cold+0x6c/0x84 mm/kasan/report.c:560\n kasan_report+0x3a/0x50 mm/kasan/report.c:585\n __kuid_val include/linux/uidgid.h:36 [inline]\n uid_eq include/linux/uidgid.h:63 [inline]\n key_task_permission+0x394/0x410 security/keys/permission.c:54\n search_nested_keyrings+0x90e/0xe90 security/keys/keyring.c:793\n\nThis issue was also reported by syzbot.\n\nIt can be reproduced by following these steps(more details [1]):\n1. Obtain more than 32 inputs that have similar hashes, which ends with the\n   pattern '0xxxxxxxe6'.\n2. Reboot and add the keys obtained in step 1.\n\nThe reproducer demonstrates how this issue happened:\n1. In the search_nested_keyrings function, when it iterates through the\n   slots in a node(below tag ascend_to_node), if the slot pointer is meta\n   and node-\u003eback_pointer != NULL(it means a root), it will proceed to\n   descend_to_node. However, there is an exception. If node is the root,\n   and one of the slots points to a shortcut, it will be treated as a\n   keyring.\n2. Whether the ptr is keyring decided by keyring_ptr_is_keyring function.\n   However, KEYRING_PTR_SUBTYPE is 0x2UL, the same as\n   ASSOC_ARRAY_PTR_SUBTYPE_MASK.\n3. When 32 keys with the similar hashes are added to the tree, the ROOT\n   has keys with hashes that are not similar (e.g. slot 0) and it splits\n   NODE A without using a shortcut. When NODE A is filled with keys that\n   all hashes are xxe6, the keys are similar, NODE A will split with a\n   shortcut. Finally, it forms the tree as shown below, where slot 6 points\n   to a shortcut.\n\n                      NODE A\n              +------\u003e+---+\n      ROOT    |       | 0 | xxe6\n      +---+   |       +---+\n xxxx | 0 | shortcut  :   : xxe6\n      +---+   |       +---+\n xxe6 :   :   |       |   | xxe6\n      +---+   |       +---+\n      | 6 |---+       :   : xxe6\n      +---+           +---+\n xxe6 :   :           | f | xxe6\n      +---+           +---+\n xxe6 | f |\n      +---+\n\n4. As mentioned above, If a slot(slot 6) of the root points to a shortcut,\n   it may be mistakenly transferred to a key*, leading to a read\n   out-of-bounds read.\n\nTo fix this issue, one should jump to descend_to_node if the ptr is a\nshortcut, regardless of whether the node is root or not.\n\n[1] https://lore.kernel.org/linux-kernel/1cfa878e-8c7b-4570-8606-21daf5e13ce7@huaweicloud.com/\n\n[jarkko: tweaked the commit message a bit to have an appropriate closes\n tag.]","modified":"2026-04-02T12:21:23.163365Z","published":"2024-11-19T01:30:49.982Z","related":["ALSA-2025:17377","ALSA-2025:9580","ALSA-2025:9581","SUSE-SU-2024:4313-1","SUSE-SU-2024:4314-1","SUSE-SU-2024:4315-1","SUSE-SU-2024:4316-1","SUSE-SU-2024:4317-1","SUSE-SU-2024:4318-1","SUSE-SU-2024:4345-1","SUSE-SU-2024:4346-1","SUSE-SU-2024:4364-1","SUSE-SU-2024:4367-1","SUSE-SU-2024:4376-1","SUSE-SU-2024:4387-1","SUSE-SU-2024:4388-1","SUSE-SU-2025:0035-1","SUSE-SU-2025:02069-1","SUSE-SU-2025:02070-1","SUSE-SU-2025:02071-1","SUSE-SU-2025:02075-1","SUSE-SU-2025:02076-1","SUSE-SU-2025:02077-1","SUSE-SU-2025:02095-1","SUSE-SU-2025:02096-1","SUSE-SU-2025:02101-1","SUSE-SU-2025:02106-1","SUSE-SU-2025:02107-1","SUSE-SU-2025:02110-1","SUSE-SU-2025:02111-1","SUSE-SU-2025:02113-1","SUSE-SU-2025:02116-1","SUSE-SU-2025:02117-1","SUSE-SU-2025:02124-1","SUSE-SU-2025:02125-1","SUSE-SU-2025:02126-1","SUSE-SU-2025:02127-1","SUSE-SU-2025:02131-1","SUSE-SU-2025:02134-1","SUSE-SU-2025:02136-1","SUSE-SU-2025:02139-1","SUSE-SU-2025:02140-1","SUSE-SU-2025:02142-1","SUSE-SU-2025:02144-1","SUSE-SU-2025:02154-1","SUSE-SU-2025:02157-1","SUSE-SU-2025:02162-1","SUSE-SU-2025:02171-1","SUSE-SU-2025:20163-1","SUSE-SU-2025:20164-1","SUSE-SU-2025:20246-1","SUSE-SU-2025:20247-1","SUSE-SU-2025:20431-1","SUSE-SU-2025:20435-1","SUSE-SU-2025:20436-1","SUSE-SU-2025:20437-1","SUSE-SU-2025:20448-1","SUSE-SU-2025:20450-1","SUSE-SU-2025:4123-1","USN-7276-1","USN-7277-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/50xxx/CVE-2024-50301.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/199c20fb7499c79557a075dc24e9a7dae7d9f1ce"},{"type":"WEB","url":"https://git.kernel.org/stable/c/1e4332581cd4eed75aea77af6f66cdcdda8b49b9"},{"type":"WEB","url":"https://git.kernel.org/stable/c/3e79ad156bedf2da0ab909a118d2cec6c9c22b79"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4a74da044ec9ec8679e6beccc4306b936b62873f"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4efb69a0e294ef201bcdf7ce3d6202cd0a545a5d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/bbad2d5b6c99db468d8f88b6ba6a56ed409b4881"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c3ce634ad953ce48c75c39bdfd8b711dd95f346f"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e0a317ad68e4ea48a0158187238c5407e4fdec8b"},{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html"},{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/50xxx/CVE-2024-50301.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-50301"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"b2a4df200d570b2c33a57e1ebfa5896e4bc81b69"},{"fixed":"c3ce634ad953ce48c75c39bdfd8b711dd95f346f"},{"fixed":"4efb69a0e294ef201bcdf7ce3d6202cd0a545a5d"},{"fixed":"1e4332581cd4eed75aea77af6f66cdcdda8b49b9"},{"fixed":"199c20fb7499c79557a075dc24e9a7dae7d9f1ce"},{"fixed":"bbad2d5b6c99db468d8f88b6ba6a56ed409b4881"},{"fixed":"3e79ad156bedf2da0ab909a118d2cec6c9c22b79"},{"fixed":"e0a317ad68e4ea48a0158187238c5407e4fdec8b"},{"fixed":"4a74da044ec9ec8679e6beccc4306b936b62873f"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-50301.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H"}]}